In my experience, copy that "sells" must evoke the impression of being unique in some way, while also conforming to certain established standards. After all, if the copy reads like something you could read anywhere else, how could the product be any different from all the competing products? Why should you pay any attention to it at all?
This requirement for conformity paired with uniqueness and originality requires a balancing act that many people who are not familiar with the task of copywriting might not understand at all. I think to some extent, LLMs are capable of creating the impression of conformity that clients expect from copywriters, but they tend to fail at the "uniqueness" part.
I don't understand. Everybody keeps telling me that LLMs are easily capable of replacing pretty much every software developer on this planet. And now they complain that $71 a day (or even $200 a month) is too much for such amazing tech? /s